The present invention relates generally to a nozzle and, more particularly, to a nozzle for an aerial refueling boom.
In a typical aerial refueling system an aerial refueling tanker incorporates a boom which extends outwardly and downwardly from the rear of the tanker. The boom is controlled by an operator in the tanker who can guide a nozzle on the end of the boom into engagement with a receptacle in the receiver aircraft.
After the boom operator has guided the boom nozzle into the receiver aircraft receptacle, latches within the receptacle are shifted by hydraulic actuators to lock the nozzle into the receptacle. Such actuators are operated automatically or by personnel in the receiver aircraft. Once the nozzle is engaged in the receptacle, then fuel can be transferred from the tanker to the receiver or, in some cases, when the tanker is low on fuel, fuel is transferred from the receiver to the tanker using receiver boost pumps.
Occasionally it is necessary to make an emergency disconnection between the boom nozzle and the receptacle in the receiver aircraft. One reason for making such a disconnection is when there is a component failure within either the receptacle or within the tanker equipment. A second reason for making such an emergency disconnection is when the receiver aircraft wanders outside of the safe operating range causing either the nozzle to be broken off from the boom, or completely breaking the boom from the tanker aircraft with corresponding hazards occurring.
At the present time, there are three methods for effecting a disconnection between the boom nozzle and the receiver aircraft receptacle. The normal method consists of personnel in the receiver aircraft actuating a control valve therein that causes the hydraulic actuator to rotate the latches in the receptacle so that they no longer engage the boom nozzle. In the second method, the receiver latch release mechanism is triggered by the boom operator in the tanker aircraft by means of an electrical signal transmitted through communications coils at the nozzle/receptacle interface. The third method is called "Brute Force" which requires decreasilng the speed of the receiver aircraft sufficiently relative to the refueling tanker either by reducing its power or by extending flaps or other drag inducing devices to put sufficient force on the nozzle and, in turn, on the latches of the receptacle to overpower the hydraulic pressure which controls the latches. The first two methods have proved to be not sufficiently reliable and the third method is somewhat dangerous and can cause aircraft damage.
A requirement has been established for an improved aerial refueling boom nozzle which allows the boom operator to make an emergency disconnection of the nozzle from the receptacle in the receiver aircraft that does not depend on operation of the receptacle latches. One method which has been proposed for achieving this result involves the use of a pneumatic actuating cylinder and a pressurized gas storage bottle for operating the latches in the boom nozzle. The requirement in such an arrangement for a pressurized gas storage bottle necessitates that the bottle be recharged before every mission of the refueling tanker. Furthermore, use of a gas storage bottle requires major modifications to be made to the boom in order to accept the bottle. Such modifications would add considerable expense to the cost of the refueling system. In addition, recharging of the gas storage bottle involves considerable maintenance service throughout the lifetime of the aircraft. Also, high pressure gas may not always be available for recharging the bottles at certain airfields where the refueling tanker may be required to land.
It is therefore the object of the present invention to provide an improved boom nozzle which may be operated by the boom operator in the tanker aircraft for making emergency disconnections from the receptacle in the receiver aircraft and does not depend upon operation of the receptacle latches, and which is relatively compact so as to not require any modification of the boom, and is relatively inexpensive to install, operate and maintain.